Diabetic Peripheral Arterial Disease versus Thromboangiitis Obliterans: A Multidimensional Comparison of Clinical Phenotype, Biomarkers, and Outcomes

Objective: This study aimed to compare thromboangiitis obliterans (TAO) and diabetic peripheral vascular disease (DPVD), the two major causes of distal limb ischemia, within a single analytical framework. The comparison was not limited to practical biomarkers that could support differential diagnosis; it was based on multidimensional parameters that determine the clinical spectrum and prognosis. The two cohorts were systematically evaluated in terms of demographics and comorbidity burden, clinical presentation and limb involvement pattern, ulcer prevalence and localization, real-life treatment strategies (medical, endovascular, and surgical), and hard clinical endpoints (major/minor amputation, hospitalization, and all-cause mortality). DPVD was phenotyped according to the lesion level as isolated distal, isolated proximal, or multilevel. Within this framework, the isolated distal diabetic peripheral vascular disease (d-DPVD) subgroup was analyzed to determine how it differs from TAO in terms of clinical course, treatment patterns, and outcomes, despite the distal anatomical similarity. Methods: In this single-center retrospective cohort study, 120 non-diabetic patients who met the angiographic TAO criteria were compared with 395 patients with DPVD with infrapopliteal/pedal atherosclerotic involvement. The clinical characteristics, ulcer topography, treatment strategies, and outcomes were recorded. The discriminatory value of blood count and lipid-based inflammatory/atherogenic indices was evaluated using logistic regression and receiver operating characteristic (ROC) curve analyses. Additionally, a separate subgroup analysis was performed for the d-DPVD subgroup, which was considered the closest to the TAO phenotype in this study. Results: DPVD was characterized by older age, higher cardiometabolic comorbidity burden, and higher inflammatory and atherogenic indices than TAO. While ulcer prevalence was similar, the distribution differed: DPVD predominantly involved plantar/proximal ulcers in a single extremity, whereas TAO more frequently involved bilateral/multiple extremities and distal acral ulcers. Antiplatelet/statin use and revascularization were more common in patients with DPVD, and major amputation, all-cause mortality, and hospitalization rates were also higher. In multivariate analyses, age, cumulative smoking exposure, SIRI, and CRI-I distinguished DPVD from TAO independently. In the d-DPVD (isolated distal) subgroup, despite a similar distal anatomical distribution, the inflammatory/atherogenic burden and clinical risk were more unfavorable. Conclusion: TAO and DPVD are two distinct phenotypes with different pathobiologies and prognoses, despite similar distal ischemia presentations. Simple inflammatory and atherogenic composite indices, evaluated in conjunction with clinical/ulcer patterns, may support differential diagnosis and risk stratification in patients with PAD. However, prospective multicenter validation of these findings is required to confirm our results.